This study provides the most recent national estimates of the prevalence of employment during nonstandard hours (evenings, nights, or rotating hours) and on weekends. It also examines in a multivariate context the relevance of job and family characteristics as determinants of such employment, separately for men and for women. The findings support the contention that the demand for employment during nonstandard hours and weekends is pervasive throughout the occupational hierarchy, but particularly in service occupations and in personal service industries and for both men and women. Gender differences exist, however, in the relevance of family factors. Being married reduces women's but not men's likelihood of employment during nonstandard hours, and the presence of children affects women's but not men's hours and days of employment. (The direction of the effect for women depends on the children's age.) Implications of these findings are discussed.